ADSL2/ADSL2plus技术分析

给出ADSL2/ADSL2plus接入技术的概念,重点分析ADSL2/ADSL2plus的编码调制、速率自适应(SRA)、能量管理、双端测试(DELT)等技术特性及其在接入应用中的具体实现,给出ADSL2/ADSL2plus一个清晰的面貌,最后对ADSL2/ADSL2plus的应用情况和发展前景进行了介绍.通过分析,使读者更清楚认识ADSL2/ADSL2plus,促进ADSL2/ADSL2plus接入在电信网中推广应用.     

浅谈全速ADSL及ADSL.lite

ADSL是近年来热门的接入网技术。本文较全面的分析了ADSL技术的基本 原理和特点,燕与其他接入技术进行了比较。针对实际应用,全面介绍了全速ADSL和简化ADSL的不同点及应用前景。     

ADSL宽带接入技术及应用

介绍了ADSL接入技术的特点和系统基本组成、对目前ADSL的单载波线路编码调制和多载波线路编码调制的两类线路编码与调制技术进行了深入比较,对ADSL传输技术的新趋势ADSL G．Lite进行了探讨,详细阐述了ADSL接入网络中Packet和ATM两种数据传输模式的特点。     

掉线不用愁ADSL宽带掉线疑难杂症揭秘

由于ADSL是电话铜线承载的一种宽带接入技术,电话线传输质量的优劣,直接影响到ADSL宽带的使用。在诸多的ADSL宽带故障,掉线问题堪称一大顽疾,也是困扰ADSL用户的一种故障。ADSL掉线的问题比较复杂,涉及到硬件和软件的问题,解决方法也非常繁琐。不过,只要精通ADSL宽带接入技术的各个环节,解决ADSL掉线疑难杂症将不再发愁。     

掉线不愁 ADSL掉线疑难杂症逐个揭秘

由于ADSL是电话铜线承载的一种宽带接入技术,电话线传输质量的优劣,直接影响到ADSL宽带的使用.在诸多的ADSL宽带故障中,掉线问题堪称一大顽疾,也是困扰ADSL用户的主要故障.ADSL掉线的问题比较复杂,涉及到硬件和软件的问题,解决方法也非常繁琐.不过,只要精通ADSL宽带接入技术的各个环节,解决ADSL掉线疑难杂症将不再发愁.     

ADSL2／ADSL2plus技术分析

给出AD6L2／ADSL2plus接入技术的概念，重点分析ADSL2／ADSL2plus的编码调制、速率自适应(SRA)、能量管理、双端测试(DELT)等技术特性及其在接入应用中的具体实现，给出ADSL2／ADSL2plus一个清晰的面貌，最后对ADSL2／ADSL2plus的应用情况和发展前景进行了介绍。通过分析，使读者更清楚认识ADSL2／ADSL2plus，促进ADSL2／ADSL2plus接入在电信网中推广应用。     

浅谈ADSL技术在农网调度自动化中的应用

由于ADSL技术具有数据传输速度快、费用低、安全可靠等优点,因此被广泛应用于农网调度自动化中。对农网调度自动化的发展现状和ADSL技术进行了阐述,介绍了ADSL技术在农网调度自动化中的具体应用,并通过实例突出了ADSL技术在农网调度自动化中的应用优势。     

ADSL技术及其在校园宿舍接入网中的应用

ADSL技术是XDSL技术中最热门的技术，本文介绍的ADSL技术及其在校园宿舍接入网中的应用，表明和现在使用的56K的Modem相比，ADSL的技术优势是不言而喻的。     

探讨异步数字用户线的调制技术

异步数字用户环路技术(ADSL)是在光纤用户网络普及之前,向用户提供宽带业务的一种过渡手段。文章比较了ADSL的三种调制技术,DMT以其性能优越和技术先进,成为ADSL的标准调制技术。     

纵谈宽带有线接入技术

有线接入技术包括：基于双绞线的ADSL技术、基于HFC网（光纤和同轴电缆混合网）的CaNeModem技术、基于五类线的以太网接入技术以及光纤接入技术。 一、基于双绞线的ADSL技术 非对称数字用户线系统（ADSL）是充分利用现有电话网络的双绞线资源,实现高速、高带宽的数据接入的一种技术。ADSL是DSL的一种非对称版本,     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).     

基于Multisim8的元件模型的导入和应用

Multisim8是一款优秀仿真软件,使用该软件可对电路进行各种参数分析。我们在享受其便利的同时,也遇到因缺少元器件导致电路仿真无法进行的阻力。解决此问题的方法就是为元件建立仿真模型并新建或扩充已有的元器件库。在不熟悉Spice编程原理的情况下,我们可通过相关网址查找到元件厂商提供的元件模型,利用模型导入的方法来建立需要的新元件。通过对新元件应用电路的仿真分析,新元件完全符合要求。在此基础上,使用元件的导入与导出功能还可对新元件进行文件备份并实现新元件在不同用户间的资源共享。     

联合外形响应的深度目标追踪器

针对追踪器使用卷积网络提取出来的特征模板进行目标位置匹配时，易产生响应噪声的问题，本文提出一种联合外形响应和卷积响应的深度目标追踪方法。在当前帧中，由前一帧提供的目标信息先分别提取卷积特征和外形信息，然后获得相应的卷积位置响应和外形位置响应；最后利用外形位置响应对卷积位置响应进行修正，从而有效地抑制响应噪声。实验表明:这种方法具有较高的位置精度，能够提高目标跟踪的准确性。     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

一种面向查询的多文档摘要方法

面向查询的多文档摘要技术有两个难点 第一,为了保证摘要与查询密切相关,容易造成摘要内容重复,不够全面;第二,原始查询难以完整描述查询意图,需进行查询扩展,而现有查询扩展方法多依赖于外部语义资源。针对以上问题,该文提出一种面向查询的多文档摘要方法,利用主题分析技术识别出当前主题下的子主题,综合考虑句子所在的子主题与查询的相关度以及子主题的重要度两方面因素来选择摘要句,并根据词语在子主题之间的共现信息,在不使用任何外部知识的情况下,进行查询扩展。在DUC2006评测语料上的实验结果表明,与Baseline系统相比,该系统取得了更高的ROUGE评价值,基于子主题的查询扩展方法则进一步提高了摘要的质量。     

An approach to the synthesis of fuzzy stabilization systems with a priori unknown model of an object

A method of synthesis of fuzzy stabilization systems for a broad class of dynamic objects under the assumption that the mathematical model of the object is not known a priori is proposed. The control is formulated in the form of a proportional law of adjustment as a function of a macro-variable; the square of the Euclidean norm of the phase variables is adopted as the macro-variable. An analogous variable characterizes the distance of the object from the equilibrium position. Despite the simplicity of the control law, its sign remains constant due to the fact that the macro-variable is positive-definite over the entire phase space. The switching times of the signals are determined by fuzzy identification of the system’s dynamic modes on the basis of measurement of the derivatives of the macro-variable.     

一种双优选的半监督回归算法

针对一些工业过程中存在的有标签样本少，而传统的半监督学习无法保证对无标签样本准确预测的问题，提出一种双优选的半监督回归算法。首先，确定有标签样本密集区中心，并计算无标签样本与该中心的相似度，实现对无标签样本的优选，同时根据有标签样本间相似度优选有标签样本；然后，利用高斯过程回归方法对选出的有标签样本建立辅学习器，以对优选出的无标签样本预测标签；最后，利用这些伪标签样本提升主学习器的预测效果。通过数值例子以及实际脱丁烷塔过程数据进行建模仿真，证明了所提方法在有标签样本较少的情况下有良好的预测性能。     

CCD camera modeling and simulation

In this paper we propose a modeling of an acquisition line made up of a CCD camera, a lens and a frame grabber card. The purpose of this modeling is to simulate the acquisition process in order to obtain images of virtual objects. The response time has to be short enough to permit interactive simulation. All the stages are modelised: in the first phase, we present a geometric model which supplies a point to point transformation that provides, for a space point in the camera field, the corresponding point on the plane of the CCD sensor. The second phase consists of modeling the discrete space which implies passing from the continous known object view to a discrete image, in accordance with the different orgin of the contrast loss. In the third phase, the video signal is reconstituted in order to be sampled by the frame grabber card. The practical results are close to reality when compared to image processing. This tool makes it possible to obtain a short computation time simulation of a vision sensor. This enables interactivity either with the user or with software for the design/simulation of an industrial workshop equipped with a vision system. It makes testing possible and validates the choice of sensor placement and image processing and analysis. Thanks to this simulation tool, we can control perfectly the position of the object image placed under the camera and in this way, we can characterise the performance of subpixel accuracy determining methods for object positioning.